“7 Boxes,” a low-budget Paraguayan crime caper goosed by low-rung dreams, crackles with the desperate energy of forced innovation. When there’s no room on the spreadsheet for fancy special effects, making do can yield its own rewards.

Set in Asunción’s largest marketplace — a sprawling maze of makeshift stalls and piled-high purchasables — the story (by Juan Carlos Maneglia, who also directed with Tana Schémbori) wrings as much mileage as it can from its clamorous location. Everyone here, it seems, is on the make; information has a price, and cellphones are more reliable currency than the Paraguayan guaraní. At least that’s what Victor (Celso Franco), a pushcart delivery boy, learns when a shady butcher offers him $100 to make seven wooden crates disappear temporarily during a police raid, then reappear when the all-clear sounds. Simple, right?

You would think. But as Victor, distracted by the television sets he lusts after and an abrasive friend (Lali González) who wants a cut of the action, trundles his loaded cart through alleys lousy with grabbers and grifters, the film evolves from wryly comedic lark to major-stakes thriller. Flinging obstacles as if they were confetti — a desperate rival for the assignment (Víctor Sosa); a pair of conflicted cops; the cargo’s menacing owners — the filmmakers stage an amazing race that almost absolves an overstuffed plot and an over-reliance on coincidence. All the while, Richard Careaga’s anxious camera skids under tables and peers up uneasily from the cart’s bouncing wheels; it knows that sooner or later we’re going to have to see what’s in those boxes.